Fact Check on Perry: Can a president 'wipe out' health law by executive order?

It's a line that Gov. Rick Perry often delivers late in his presidential pitch, shortly before the crescendo that leads into "God bless you, and God bless America."

"One of the first thing's I'll do as president of the United States is sign an executive order to wipe out as much of 'ObamaCare' as I can," he tells primary-state voters.

That promise unsurprisingly prompts cheers from conservative audiences -- and it, on its face, is more immediately realistic than an outright promise to repeal the law wholesale, which would require congressional approval.

But can he actually change the law in a meaningful way with just an executive order?

Yes and no, legal experts say.

A president cannot use an executive order to dismantle or nullify a law that has been passed by Congress, experts point out, but he or she could tinker with the execution of the law.

"What Perry is doing is saying he will use whatever authority is available to him to interfere with the law's Implementation," says Professor Kenneth Mayer of the University of Wisconsin, an expert on executive orders. "There are bits and pieces he could do but as far as nullifying a law, that wouldn't be within his authority."

The "bits and pieces" include the granting of waivers to entities that might have been affected by the legislation (something the Obama administration has already done), or the delay of issuing rules for states' insurance exchanges, Mayer says.

Professor Stephen Vladeck of American University says that a president could theoretically direct federal agencies to be "lackadaisical" in their enforcement of the law's regulations. Perry could order the Internal Revenue Service and the Department of Health and Human Services to "focus their efforts elsewhere," he added, although a president cannot directly instruct agencies to completely drop execution of a law.

But even those actions could face constitutional questioning.

"It falls into a really gray area of constitutional law about the president's discretion to NOT enforce a law," says Vladeck.

Assuming that the court has not already weighed in on the constitutionality of the legislation, a private citizen could sue the federal government for failing to enforce the health law. And it remains an open question whether a president has the constitutional authority to undermine an existing law from the White House alone.

"There's actually not a ton of case law on where the line is between the president's power NOT to enforce and the president's obligation to enforce," Vladeck says.

The question may be mute If the Supreme Court has ruled on the pending challenges to the law's individual mandate by the time (and, of course, if) a new Republican president is elected.

That's an outcome Perry wouldn't mind.

"Now hopefully, Lord willing, the 11th Court of Appeals has already found that that individual mandate is unconstitutional, and hopefully that will be gone to the Supreme Court," Perry said in South Carolina last week. "And I won't have to deal with that."